The Rural Voice, 2002-06, Page 28Lying in wait
Research shows weed seeds can lay dormant for many years before springing to life.
In fact an archaeological excavation of a 600 -year-old site in Denmark found
mustard seeds that were still viable.
Story and photo by Larry Drew
Growing up on a farm before
the wide spread use of
herbicides meant growing up
with a hoe in your hand.
As a young boy, I knew the weeds
would be waiting to test the
persistence of my siblings and me as
soon as school was out for the
summer — but just how persistent
the weeds could be and just how long
some of them were prepared to wait
for this annual showdown is simply
amazing.
For sure, it was "a long row to
hoe", but we anxiously worked
through dad's fields, knowing that
once we were through, we could then
earn some money by hiring ourselves
out to neighbours who needed an
extra crew to hoe their fields.
Between each time through with a
hoe, the tractor was cranked and the
field mechanically cultivated
between the widely spaced rows,
clearing away more weed seedlings
and coaxing even more weeds to
germinate. We repeated this ritual
three to four times each season as we
worked back and forth through dad's
fields and then our neighbours' fields
for much of the summer. And to
think, I might have even hoed a weed
a two that grew from a seed that
dropped from a weed that my great -
great -grandfather had missed with his
hoe.
In 1879, the famous Beal
experiment was started when 20 open
jars, each containing 50 seeds of
various weed species, were buried
about 20 inches below the surface.
Every 5 to 10 years a jar was dug up
and the seeds tested for germination.
Some pigweed seeds remained viable
after being buried for 40 years.
Remarkably, about 20 per cent of the
species from jars that were dug up
some 75 years after the experiment
had began, still produced viable
seeds.
While the results of experiments
on seed dormancy and persistence
vary with the conditions and type of
study, according to the Oregon State
University Extension Service (OSU)
most seeds that can persist for
decades are broadleaves, while grass
seeds tend to be less persistent — but
with many exceptions. While it
appears that Quackgrass may retain
A lane on the author's family farm
(below) had been grassed and
showed no signs of velvet leaf but
after it was plowed up, it came
back as solid velvet leaf.
24 THE RURAL VOICE